USB FLASH drive repair

During the last years I repaired quite a lot of USB FLASH drives where the owners weren't able to read out the data anymore. Most of them were SanDisk Cruzer types. You can find a lot of complaints about failures online.

All of them had one thing in common: A hardware failure which was easy to repair.

First let's take a look at a common USB 2.0 thumb drive (or USB stick) design. There's not much components to see when they are naked.

The main part is the USB controller. In this case it is a USBest U165. Sometimes there is a hickup in the controller. There are utilities on the web which you can use to repair this. Have a look at this example or use Google to find software for your controller. But you will loose your data most likely. Also, that turned out not to be the problem on all the USB drives I repaired.

A closer look at the other side reveals this:

You can see the FLASH IC on the right side. That's where the data is stored. This could also fail and your data is lost forever. But you may check if all pins are soldered correctly and that there is no crack at one ore more pins.

But the part which was broken on ALL the sticks I got hand on during the past years was the crystal.

For those of you who are not familiar with crystals (which are used for clock generation, in this case for the USB controller): Usually they have a thin "glass" inside which oscillates. Here is a picture by Chribble76 taken from Wikipedia (Public Domain).

As you can see, this structure can easily break if you throw around your thumb drive. If it cracks or a small piece breaks off, it will not have its specified frequency anymore and thus the USB controller wil not work (properly). After frequency measurements with a plugged in USB stick, I noticed that the XTAL frequency was not 12MHz, but close to 11 MHz. This caused the error that the stick was constantly dis- and then reappearing in the operating system within seconds. With this behaviour you do not even have the slightest chance of using data recovery tools or oftware to repair your controller.

So what I did to repair all the USB FLASH drives was simply to desolder the broken XTAL and replacing it with a good one. If your stick breaks at a weekend, you can use a crystal taken from a good USB drive.

Often there are more than one solder pads to accomodate different XTAL packages.

all of the USB drives I repaired with the above error had the tiny can type crystals. So I cannot speak for other XTAL types in conjunction with USB-Sticks. But I know from my work that they should be the ones most susceptible to mechanical damage. If the glue comes lose, also their thin leads easily break.
12 Hz is funny :) Do you remember which TV show they talked about this?

Your description of repairing the oscillator on a 2.0 flash drive looks very similar to what I need someone to do for one of my flash drives. It is a XDigital Tavel Warrior 8 GB. The metal cover came off and the oscillator broke off completely. It has two prong sticking out, one of which has a small pad at the end of it, which needs to be reattached to the little board. (I can send a picture if that would help.) What are the risks of a professional trying to repair this before undertaking some kind of data recovery? I am very concerned not to lose the data. I don't really care about re-using the flash drive.

yes, this could also work with a USB 3.0 stick. If you cannot find a crystal, you can send me a picture of the opened stick and I can point you to it. My contact data is listed here in the Blog under "about".

hard to say if the crystal is not properly working. Do you have a frequency counter or scope so that you can measure its frequency? If not you may want to replace it with a good one and see if ste stick comes to life again...

hello, I have a USB thumb drive I need to recover. It just quite this week for no apparent reason. However after taking it apart I do not find a crystal as shown in the pictures in the post. What to do?

If you can, send a picture (preferably high resolution) of both sides of the thumb drive PCB. I then can point you to the location of the xtal. Do you have skills to solder a new one or do you know people who can assist you?

if you are able to send me a photograph of your flash drives with the exposed PCBs, I should be able to mark the crystals for you.
You are right, it requires some skill, at least to de-solder the existing crystals without damaging components around. If you solder a new crystal, it is a little more relaxed.
Contact me, if you need more help, you'll find my email address under the "About" link on the right.

I've just received confirmation from a data recovery company saying my crystal has broken. I was looking around the internet as to what can be done regarding this and stumbled upon your website. I don't know how to do this kind of work but need to recover my files (which include some childhood photos). I was wondering if you would be able to fix this (or can recommend someone to) if I were to send my 64GB Lexar flashdrive to you?

Flo, I think you have bad luck with your thumb drive. Indeed, there is no crystal soldered to the PCB. The pictures you send me are low resolution, but I could spot that the controller is a ALCOR one. Their FLASH disk controllers do have an embedded xtal in the chip: http://www.alcormicro.com/en_content/c_product/product_02b.php?CategoryID=3&IndexID=13
You would have to get hold of an Intenso stick with the same controller and exhcange it to get to your data. Hope this could work, because sometimes the controller has embedded memory for managing data of the attached memory chips (bad blocks, etc.)

Sorry for low resolution, i wanted just save place on your emailbox . I will replace the same controller from the new one (are identical) even the architecture is completly different. On this one the mem are soldered under and the new one has normal pins. I hope it'll be able to do it and if you have any other advices for me , it will be greatfull. Thank's a lot Florin

seems you are unlucky as Flo2. The PCB shows no crystal, so it must be integrated into the controller (ITE1171E-480). But on the top side (where the big FLASH IC resides), there are 4 empty solder pads. Those are for a crystal. Unfortunately I cannot find a datasheet for the controller. So I do not know how external crystal operation is activated. You cold try soldering a crystal to those pads and if you are very lucky, the thumb drive will come back to life! (But I have my doubts...)

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